318i fuel pump issue.

[craigsaxon]

Hi guys, new to the forum. Just been given a late '89 post facelift e30 318i that's not working. Got spark when I turn it over but the fuel pump is not working at all. Pulled the relay and bench tested it, works fine. Put a test light on the fuel pump fuse, no power either side of it. The ignition key that I have is an aftermarket cut key. do I need a key with an electronic code? Is there a factory immobiliser on e30's that works on the fuel pump circuit? If so, is there a way to bypass it or disable it. Any other suggestions for the possible culprit? Can I simply hot wire the pump or is there anything else that an immobiliser or the ecu does that would cause this problem? It's got me stuffed......

[Brianmoooore]

No chips in keys and the BMW immobiliser doesn't work on the fuel pump circuit, although they were dealer installed, and it's possible that the fitter that installed it got creative and didn't follow factory instructions.
Fuel pump fuse isn't live with ignition - only when the engine is turning.
Pull out the fuel pump relay and link together pins 30 and 87 of its base with a short piece of wire. This should make the fuel pump run. Ignition does not need to be on, and the pump should be easily heard without an engine masking its noise.
If the pump doesn't run, pull off its plug, and connect a 12 volt lamp (5W minimum) to the plug. If it lights, the pump is probably dead. Push the plug back on, and thump the top of the pump hard with something like a hammer handle or a long socket extension bar. There's a good chance the pump will come back to (temporary) life.
If the bulb doesn't light, then there's possibly an aftermarket immobiliser somewhere in the circuit. Maybe more than one.
The record I've come across is three immobiliser/alarms, all still connected, and all not in use.

[craigsaxon]

Thanks Brian, will give it a go in the morning and report back.